Scientific Papers. Series B, Horticulture. Vol. LXIII, No. 2, 2019 Print ISSN 2285-5653, CD-ROM ISSN 2285-5661, Online ISSN 2286-1580, ISSN-L 2285-5653

RESEARCH ON THE PRODUCTION, BEHAVIOUR AND EVOLUTION IN TERMS OF GROWTH AND DEVELOPMENT OF SOME SUCCULENT , IN ORIGINAL SUPPORT STRUCTURES

Sorina PETRA, Florin TOMA, Cristina MĂNESCU, Mihaela GEORGESCU, Elisabeta DOBRESCU, Andreea BUNEA

University of Agronomic Sciences and Veterinary Medicine of Bucharest, 59 Mărăști Blvd, 011464, Bucharest, Romania

Corresponding author email: [email protected]

Abstract

At worldwide scale, the tendency concerning the indoor decoration with plants is to use some original and functional structures to support them. The design and achievement of the support prototype may have not only an aesthetic role, but also of fixing and providing an optimal substrate, with subsequent implications in plants’ growth and development. The chosen support together with different materials such as: moss, peat, tree bark, fragments of twigs or roots with special forms, sand, gravel or other materials arranged in harmony with material, amplify the decorative effect of the final product. Selection and association of plants in such structures are essential. These should not be based only on aesthetic principles and the size of individuals, but also on the requirements of plants for environmental factors, very close to the plants` growth rate and development, so they preserve decorative aspect as much as possible. The aim of this research was to conceive and realize the support prototype and then to investigate the behaviour and evolution of some succulent indoor plants regarding their growth and development after installation on support.

Key words: succulent plants; concept; support; decorative.

INTRODUCTION succulent plants (Gideon et al., 2017; Sandoval, 2017) are still modest. Succulent species are highly appreciated plants The present research presents new and original by flower lovers (Stead, 2016; Toma, 2009). supports prototype for succulent plants, which They are important floral assortment through were then investigated indoors for their their special decorative potential and very behaviour and development in time. Our work varied propagation, culture and use possibilities was based on many previous researches (Baldwin, 2017; Change, 2012; Maggio, 2016). regarding the production and use of succulent Equally, succulent plants are the subject of plants in different crop varieties. numerous researches with a very broad subject. Enrichment of the assortment with new species MATERIALS AND METHODS and varieties having special decorative potential is frequently considered in studies I. Production of cuttings. Seventeen succulent (Pino, 2005; Thulin, 2002). Also, many studies plant species were selected to produce by and researches used prototype supports for a cuttings the plant material necessary to cover large number of succulent species in different supports. The selected species were as combinations that have decorative impact and follows: Kalanchoe tomentosa Baker, in the same time are functional in many Bryophyllum fedtschenkoi Raym.-Hamet & H. variants of interior spaces (Harvey, 2016; Starr, Perrier, nussbaumerianum Bitter, Sedum 2016). Other research is focused on the allantoides Rose, Sedum rubrotinctum R.T. possibilities of propagation, including in vitro Clausen, Sedum pallidum var. bithinicum propagation methods (Cabahug et al., 2016). Gibson, Sedum burrito Walther, Echeveria Researches on the behaviour of succulent gibbiflora DC, Graptopetalum paraguayense plants in different types of climate (Zeevaart, Walther, Crassula perforata var. variegata 1982; Kelaidis, 2008) or the taxonomy of Thunb, Aeonimum arboretum Webb & Berth., Aeonimum haworthii Webb & Berth., Cyanotis 195 somalensis CB Clarke, Senecio mandraliscae peat, V2 - sand, V3 - perlite, V 4 - peat (50%) Rowley, Senecio kleiniiformis Suess., + sand (50%), V5 - peat (50%) + perlite Messembryanthemum crystalinum L., (50 %). Corpuscularia taylorii Schwantes. For all these species were made top shoot cuttings with length between 4 and 8 cm, depending on the species (Bala, 2012; Selaru, 2006). Once made, the cuttings were left to dehydrate in plastic crates for 6 days (Figure 1).

Figure 2. Substrates used for rooting the cuttings

Researches of various authors showed that the rooting time of the cuttings varies from a few days to a few weeks, depending on the species, the rooting substrate, climate or rooting stimulators applied (Cabahug et al., 2016; Cantor, 2016). Eight weeks after planting, all the cuttings were rooted (Figure 3) and removed from the substrate.

Figure 1. Cuttings left to dehydrate

Before planting in the rooting substrate, the height and the number of leaves of the cuttings of each species was noted (Table 1). Table 1. The cuttings features No Species Height Leaves No. of crt. (cm) no. cuttings 1. Kalanchoe tomentosa 6 7 10 2. Kalanchoe fedtschenkoi 8 8 10 3. Senecio mandraliscae 6 8 10

4. Senecio kleiniiformis 8 8 10 5. Echeveria gbbiflora 4 5 5 Figure 3. Cuttings root 8 weeks after planting

6. Crassula perforata var. 5 10 5 variegate The following observations and measurements 7. Graptopetalum 5 11 5 were made: rooted cuttings height (cm), paraguayense 8. Messembryanthemum 6 14 10 number of leaves, branches, branch length crystalinum (cm), maximum root length (cm), number of 9. Corpuscularia taylorii 7 6 10 main roots, length of main roots (cm), number 10. Sedum 5 14 15 nussbaumerianum of secondary roots, the length of the secondary 11. Sedum allantoides 5 25 10 roots (cm). 12. Sedum rubrotinctum 6 25 15 II. The growing of rooted cuttings in pots. 13. Sedum bithinicum 4 15 10 The eight-week-old rooted cuttings were 14. Sedum burrito 4 25 10 planted individually in 5 cm pots (Figure 4). 15. Cyanotis somalensis 4 8 15 The substrate media used was consisted of 16. Aeonimum arboreum 5 25 30 celery soil, leaf soil, peat and sand in a ratio of 17. Aeonimum haworthii 5 14 5 1: 1: 1/2: 1/3 plus chunks of 10% clay. Total no. of cuttings 185 After planting, a set of observations and measurements were made: plant height, the Five substrate variants (Figure 2) were used to number of leaves and shoots and the length of root the cuttings of all species, as follows: V1 - shoots (cm).

196 half hours. A total of 187 cuttings of different succulent species were used to cover the sphere and the working time for planting was 6 hours (Table 2, Figure 6).

Figure 4. The aspect of plants after planting in pots

III. Designing and making structures with succulent plants. For several years, many publications and researches have been devoted to the creation and maintenance of different types of unconventional culture supports with succulent plants (Cammidge, 2019; Daigle, 2015). In this research we made and analyze three variants of such supports. First support was represented by a large decorative sphere (diameter 20 cm) made up of two sections of rigid wire (with a diameter of 5 mm) and covered in wire mesh (Figure 5). Figure 6. The planting on large sphere Table 2. Species used for cover the large sphere No. Species No. of rooted crt. cuttings

1. Kalanchoe tomentosa 5 2. Kalanchoe fedtschenkoi 15 3. Sedum nussbaumerianum 10 4. Senecio mandraliscae 12 5. Senecio kleiniiformis 7 6. Echeveria gibbiflora 2 7. Crassula perforate var. 13 variegata 8. Graptopetalum paraguayense 3 Figure 5. Forming the large sphere 9. Messembryanthemum sp. 12

The inner walls of the sphere were lined with 10. Corpuscularia taylorii 10 vegetable moss and the core filled with peat. 11. Sedum allantoides 26 Peat was chosen because is a very light 12. substrate, thus maintaining a low weight to the Sedum rubrotinctum 4 sphere. Then the two sections were fixed to 13. Sedum bithinicum 4 each other with wire, clamped around the 14. Cyanotis somalensis 13 equator, resulting in the large sphere. After 15. Aeonimum arboretum 40 joining, a ring and a decorative chain needed for hanging the sphere was attached. The 16. Aeonimum haworthii 7 working time for this prototype was two and a Total rooted cuttings: 187 197 The second support was a small decorative used a wooden photo frame of 20 x 15 cm sphere (diameter 10 cm). The construction behind which was attached another wooden technique of the sphere was identical with that framework of 5 cm height and a wooden presented previously at the large sphere, the plywood, necessary to support the substrate. single difference being the size (10 cm Also, a wire mesh was fixed in the space for diameter). In this case, before join together the photography. Over this it was supplemented sections these were covered first with succulent with muscle and then peat was used as plants (Figure 7). substrate (Figure 8).

Figure 8. The appearance of decorative photo frame

Before attaching the back plywood, a plastic foil was placed over the peat to protect it from moisture generated by the water used for watering. The working time for making this prototype was one and a half hours. It was necessary a 33 Figure 7. Forming and planting the small sphere cuttings of 14 species of succulent plants to cover the frame. The working time necessary The working time for making this prototype for planting the support was 1 and a half hours was two hours. For the small sphere, we used (Table 4). 78 rooted cuttings belonging to 12 species, and the working time for planting was 4 hours Table 4. Species used in the decorative photo frame (Table 3). No Species No. of crt. rooted Table 3. Species used for the small sphere cuttings 1. Kalanchoe tomentosa 3 No. Species No. of 2. Kalanchoe fedtschenkoi 1 crt. rooted 3. Sedum nussbaumerianum 3 cuttings 4. Senecio mandraliscae 5 1. Kalanchoe tomentosa 3 5. Echeveria gibbiflora 1 2. Sedum nussbaumerianum 6 6. Crassula perforate var.variegata 3 3. Senecio mandraliscae 10 7. Graptopetalum paraguayense 1 4. Echeveria gibbiflora 2 8. Sedum alantoides 1 5. Crassula perforate var.variegata 3 9. Sedum rubrotinctum 2 6. Graptopetalum paraguayense 2 10. Sedum bithinicum 1 7. Corpuscularia taylorii 5 11. Cyanotis somalensis 2 8. Sedum alantoides 7 12. Aeonimum arboreum 3 9. Sedum rubrotinctum 8 13. Sedum burrito 5 10. Cyanotis somalensis 11 14. Aeonimum haworthii 2 11. Aeonimum arboreum 18 Total rooted cuttings: 33 12. Aeonimum haworthii 3

Total rooted cuttings: 78 The height of the plants, the number of leaves,

the number and length of shoots, the diameter The third support was a decorative photo of the plants and the moment of flowering were frame with succulents. For this support it was 198 determined to establish the degree of growth of nine months this achieve a value of 17.98 cm the plants. (Figure 11).

RESULTS AND DISCUSSIONS Table 5. Cuttings roots characteristics on different substrate Species Var. Length No. of No. of I. Production of cutings of roots primary secondary (cm) roots roots The data shows that the percentage of rooting Kalanchoe V1 7.00 9.0 12.0 V2 3.75 13.5 11.5 varied between 72.90% at variant V4, substrate tomentosa V3 3.20 21.0 27.5 V4 2.75 10.0 - peat (50%) + sand (50%) and 94.50% at variant V5 2.50 9.5 - V3, perlite. Senecio V1 11.00 5.5 19.0 V2 - - - The rooting quality varied with species kleiniiformis V3 3.50 6.0 15.0 V4 5.50 5.0 7.0 substrate used (Table 5, Figures 9-10). V5 9.00 6.0 12.5 Kalanchoe V1 11.25 10.0 8.0 V2 10.75 7.5 35.0 fedtschenkoi V3 6.75 7.0 27.5 V4 7.75 9.5 17.5 V5 9.00 10.5 10.5 Sedum nuss- V1 2.50 2.5 3.5 V2 3.00 5.0 6.5 baumerianum V3 2.75 5.0 8.0 V4 - - - V5 2.50 3.5 - Cyanotis V1 17.00 10.5 5.0 V2 13.25 3.5 3.5 somalensis V3 14.50 2.5 4.5 V4 12.25 5.5 6.0 V5 11.75 7 4.0 Senecio V1 - - - V2 2.00 2.0 - mandraliscae V3 4.50 2.5 6.5 V4 2.00 2.5 3.0 V5 0.85 3.0 3.0 Sedum V1 4.25 1.0 3.0 V2 5.25 8.5 14.5 rubrotinctum V3 3.25 5.5 9.0 Figure 9. Differences between cuttings in terms of length V4 3.00 3.5 10.0 and rooting at Kalanchoe fedtschenkoi (left side) and V5 4.75 7.0 13.0 Aeonimum V1 2.75 2.5 2.0 Cyanotis somalensis (right side) V2 4.00 6.5 7.5 arboreum V3 2.50 5.0 2.5 V4 3.25 5.5 3.0 V5 3.25 5.0 5.0 Messem- V1 3.25 2.5 - V2 6.75 7.0 6.5 bryanthemum V3 12.00 4.5 6.5 crystalinum V4 2.25 2.0 - V5 12.00 6.5 5.0 Grapto- V1 4.50 7.0 5.0 V2 3.50 7.0 - petalum V3 2.00 8.0 - paraguayense V4 2.20 5.0 - V5 3.50 6.0 - Sedum V1 11.00 2.5 - V2 6.40 2.5 - bithinicum V3 6.00 3.0 2.0 V4 8.75 3.0 2.5 V5 10.50 3.5 3.0 Sedum burrito V1 4.50 0.5 - V2 4.25 1.0 - Figure 10. Species with indefinite growth: V3 4.75 1.0 - V4 3.75 1.0 - a) Messembryanthemum crystalinum; b) Corpuscularia taylorii; V5 3.50 2.0 - c) Kalanchoe fedtschenkoi; d) Sedum bithinicum; Crassula V1 6.00 3.0 - e) Senecio kleiniiformis V2 4.50 4.0 - perforata V3 5.50 3.0 - variegata V4 4.00 5.0 - From the 17 initial species, only the cuttings of V5 5.00 2.0 - Echeveria V1 10.00 4.0 - Aeonimum haworthii did not rooted on any V2 3.50 3.0 - gibbiflora V3 3.50 1.0 - substrate tested. V4 11.00 4.0 - V5 - - - Corpuscu- V1 11.50 5.0 - V2 11.00 5.0 - II. The growing of rooted cuttings in pots. laria taylorii V3 9.50 5.0 - V4 - - - The results obtained by the rooted cuttings of V5 23.50 6.5 - the 16 species, after planting in Sedum V1 2.50 3.0 - V2 7.25 8.5 - pots, showed a different reaction in their allantoides V3 8.25 4.5 - V4 - - - growth (Table 6-7). At planting time, the V5 - - average height of plants was 5.23 cm and after

199 After nine months of growing in pots, most of the succulent plants branched and considerably increased the number of leaves (Table 7). The most thickest and compacted plants were Sedum alantoides, Sedum rubrotinctum and Cyanotis somalensis.

Table 7. Plants measurements after nine months Length of No. of Leaves no. branch branch. (cm) a Species

after 9 after 9 after 9 after months months months at planting at planting at planting

Kalanchoe tomentosa 8.5 34.5 - 4.0 - 4.1 Kalanchoe fedtschenkoi 16.5 36.5 - 2.5 - 10.0 Sedum nussbaumerianum 16.5 41.5 - 2.5 - 3.8 Senecio mandraliscae 5.5 29.0 - 0.5 - 4.0 Senecio kleiniiformis 13.5 41.0 - 3.5 - 6.3 Echeveria gibbiflora 5.0 20.5 - 0.5 - 2.0 Crassula perforata 14.0 45.0 - 1.5 - 4.0 var.variegata Graptopetalum 9.5 44.0 - 1.0 - 9.2 b paraguayense Figure 11. The aspect of plants at planting (a) Messembryanthemum 14.5 98.0 3 55.0 1 23.5 and after nine months (b) crystalinum Corpuscularia 6.0 19.5 - 6.5 - 1.5 In nine months, five species - Kalanchoe Taylorii fedtschenkoi, Senecio kleiniiformis, Sedum alantoides 15.5 70.5 - 6.5 - 6.5 Sedum rubrotinctum 21.5 88.0 4 13.5 2 6.6 Mesembryanthemum crystalinum, Sedum bithinicum 18.5 93.0 3 5.5 1.8 4.9 Corpuscularia taylorii and Sedum bithinicum Cyanotis somalensis 9.0 78.5 5 10.5 2 4.8 reached considerable heights of 20-45 cm Aeonimum arboreum 15.0 98.0 1 3.0 1 4.5 (Figure 10). Sedum burrito 19.5 73.5 - 1.5 - 1.1

Consequently, these succulent plant species, Regarding the viability of plants after nine with indefinite growth, were considered months after planting, it was establish that only inappropriate for use in such decorative 7% from the total plants were lost (Table 8). systems (sphere and photo frame). Table 8. Plants viability in potted culture Table 6. Height of potted plants (cm) Species Initial No. after % of h after no. nine viability h at Species nine months planting months Kalanchoe tomentosa 10 10 100 Kalanchoe tomentosa 5.50 14.45 Kalanchoe fedtschenkoi 10 10 100 Kalanchoe fedtschenkoi 13.25 44.50 Sedum nussbaumerianum 12 12 100 Sedum nussbaumerianum 6.60 12.75 Senecio mandraliscae 7 5 71 Senecio mandraliscae 3.90 15.00 Senecio kleiniiformis 7 7 100 Senecio kleiniiformis 9.25 20.50 Echeveria gibbiflora 4 4 100 Echeveria gibbiflora 3.50 10.50 Crassula perforata var.variegata 5 5 100 Crassula perforata var.variegata 2.75 13.50 Graptopetalum paraguayense 5 5 100 Graptopetalum paraguayense 3.50 19.00 Messembryanthemum crystalinum 10 10 100 Messembryanthemum crystalinum 5.95 39.50 Corpuscularia taylorii 8 3 37 Corpuscularia taylorii 4.70 21.50 Sedum alantoides 6 2 33 Sedum alantoides 3.25 13.50 Sedum rubrotinctum 15 15 100 Sedum rubrotinctum 7.50 18.50 Sedum bithinicum 10 10 100 Sedum bithinicum 5.25 21.50 Cyanotis somalensis 14 14 100 Cyanotis somalensis 3.00 5.25 Aeonimum arboreum 26 26 100 Aeonimum arboreum 4.07 11.25 8 8 100 Sedum burrito 1.75 10.25 Sedum burrito

200 In several months after planting, five of sixteen cuttings of the 16 species had a percent of 88.7%. species flowered (Figure 12). Losses of cuttings were noted at Senecio kleiniiformis, Mesembryanthemum crystalinum and Corpuscularia taylorii, the last one, with the most severe losing (100%). In this system, the association of plants proved to be approximately successful, since only two of the species - Kalanchoe tomentosa and Crassula perforata variegate, were partially covered by the rest of the species (Figures 13- 14).

Figure 12. Flower details at: a) Messembryanthemum crystalinum; b) Cyanotis somalensis; c) Senecio kleiniiformis; d) Kalanchoe fedtschenkoi; e) Aeonimum arboreum

The length of the flower stems varied between 3.5cm at Aeonimum arboreum and 45cm at Senecio kleiniiformis (Table 9).

Table 9. The variation in the quality of the floral elements and the flowering time

Species (cm) of flowers stems stems No. of No. of flower flower flowers/stem flowers/stem No. of flower Height of stem Color Color Timeof flowering

Senecio 45 1 10 yellow XI kleiniiformis Messembryanthemum - - 1 white X crystalinum Figure 13. Initial form of the large decorative sphere Kalanchoe 10 1 10 orange XII fedtschenkoi Aeonimum 3.5 5.5 11 yellow XII arboreum Cyanotis - - 3.5 violet I somalensis

Two of the species, Mesembryanthemum crystalinum and Cyanotis somalensis, bloom directly on shoots, consequently they do not have flower stems. The number of stems per plant ranged from 1 to 5-6 flower stems/plant. The number of flowers on a stem varies from one single flower and reaches up to 11 flowers. The colour of the flowers was: white, yellow, orange and purple. For most of the species, flowers do not smell, except Senecio kleiniiformis, whose odour is strong and unpleasant. The flowering period was between October and January. III. Designing and making structures with Figure 14. The large decorative sphere after one year succulent plants. Results of studies on the Leaf decay and loss was also observed in the large decorative sphere (diameter 20 cm) case of the species: Aeonimum arboretum, showed that after planting, the viability of the 201 Sedum rubrotinctum, Graptopetalum association of plants in this system was paraguayense, Sedum alantoides and Echeveria successful. Plants developed harmoniously, gibbiflora. without invading each other. Still, similar with In December, some of the species, such as the plants of large sphere, the plants of smaller Kalanchoe fedtschenkoi, Aeonimum arboreum sphere presented leaf decay and loss at and Mesembryanthemum crystalinum have Aeonimum arboretum, Sedum rubrotinctum, blossomed. Graptopetalum paraguayense and Sedum Data results in the case of the small decorative allantoides (Figure 17). sphere (diameter 10 cm), the cuttings survived better than previously structure. For this sphere of smaller size covered with 12 species, the viability of cuttings had a percent of 93.5% (Figures 15-16).

Figure 17. Leaf loss at sphere system: a) Aeonimum arboretum; b) Sedum alantoides and Sedum rubrotinctum; c) Graptopetalum paraguayense; d) Echeveria gibbiflora

The only species that developed flowers in this system was Aeonimum arboretum, in December. The observations made in the case of the decorative photo frame with succulents, indicated an excellent survival of the cuttings. All the 14 species cuttings rooted and

developed without any lost (Figures 18-19). Figure 15. Initial form of the small decorative sphere Consequently, the association of plants in this system was considered successful. During one year, plants developed harmoniously, without invading each other.

Figure 16. The small decorative sphere after one year

Only the cuttings of Corpuscularia taylorii were entirely lost, therefore we considered that the Figure 18. Initial form of the decorative photo frame 202 with smaller rooting percent were: sand - 86%, peat 81% and peat+sand - 72.9%. One of the species (Aeonimum haworthii) failed to root on all five tested substrates.

II. The growing of rooted cuttings in pots. Regarding the evolution of the selected species, it was found that not all the 16 species selected originally are suitable for planting in structures. This occurs because Kalanchoe fedtschenkoi, Senecio kleiniiformis, Mesembryanthemum crystalinum, Corpuscularia taylorii and Sedum bithinicum had a faster growth rate, reaching in a relatively short period of time 20 cm height or more. Therefore, these species exceed, invading and compete the other plants and finally changing the shape and the harmony of plant association of the structures. A percent of 31.25% from the tested species

initiated and developed flowers. Figure 19. The decorative photo frame after one year After nine months of planting, the cuttings

The species that developed flowers were viability was of 92.9%. Aeonimum arboreum and Kalanchoe fedtschenkoi. The leaf decomposition was noted III. Designing and making structures with at five species: Sedum alantoides, Sedum succulent plants. The design and construction rubrotinctum, Sedum bithinicum, Graptopetalum of sphere-type structures is recommended to be paraguayense and Kalanchoe fedtschenkoi done in two sections, which can be easily fill (Figure 20). and assembled. Also, such systems must be made of durable materials, wire and wire mesh, in order to maintain the spherical shape. Regarding the realization of the structure of the photo frame, it was noted that the wood used as material for sustain the substrate and plants, did not deteriorate over time. Anyway, it is recommended to protect structure on the outside at the time of spraying water. The percentage of viability of the non-rooted cuttings planted in the three decorative structures was different: 88.7% at the large decorative sphere, 93.5% at the small decorative sphere and

100% at decorative photo frame. The species Figure 20. Leaf loss at the photo frame system: a) Sedum Corpuscularia taylorii recorded a plant loss of bithinicum; b) Sedum rubrotinctum; c) Kalanchoe fedtschenkoi; 100% for both types of spheres. Another two d) Sedum allantoides; e) Graptopetalum paraguayense species, Senecio kleiniiformis and

Mesembryanthemum crystalinum were lost in the CONCLUSIONS case of large sphere.

Regarding the evolution of the species used in I. Production of cutings. Data of this sphere-type systems, it was noted that five experiment showed slightly variation between species, Mesembryanthemum crystalinum, Sedum species and substrate used for rooting. The best bithinicum, Sedum rubrotinctum, Sedum rooting results obtained for the cuttings of 16 alantoides and Graptopetalum paraguayense, species were on two substrates: pearlite require a guidance of shoots among the wire at (94.5%) and peat+perlite (89%). The substrates 203 the moment where they exceed the spherical Moore, K.G. (2008). Hardy Succulents: Tough Plants for contour of the structure. Every Climate. Storey Publising. 210 MASS MoCa Way. North Adams MA 01247. The development of the species in the decorative Pino, G. (2005). Echeveria andicola. a new species from photo frame was remarked to be much faster at central Peru. Haseltonia, 11. 98-102 (1 December Sedum alantoides, Sedum rubrotinctum and 2005).https://doi.org/10.2985/1070- Sedum bithinicum. So, we recommend to plant 0048(2005)11[98:EAANSF]2.0.CO;2 these species at the base of the structure, so that Sandoval, E. (2016). Liberate Your Succulents! BioOne Complete. Cactus and Suculents Journal, 88(5) (1 the subsequent growths did not cover and September 2016). https://doi.org/10.2985/015.088.0507 compete the other species. Selaru, E. (2006). Indoor plants, second edition (in Romanian). Publishing House Ceres. Smith, G.F., Figueiredo, R., Mort, M.E. (2017). REFERENCES Taxonomy of the three arborescent crassulas. Crassula arborescens (Mill.) Willd. subsp. Aone, C.R., Soh, S-Y., Nam, S.Y. (2016). Effects of arborescens. C. arborescens subsp. undulatifolia Auxin and Cytokinin Application on Leaf Cutting Toelken. and Crassula ovata (Mill.) Druce Propagation in Echeveria Species. Flower Res. J. 24 () from southern Africa. Bradleya (35). (4), 264-273 DOI 87-105. https://doi.org/10.25223/brad.n35.2017.a8 http://dx.doi.org/10.11623/frj.2016.24.4.04 Starr, G. (2016). The Three Rs of Landscaping with Bala, M. (2012). General and Special Floriculture (in Succulents. BioOne Complete. Cactus and Suculents Romanian). Ed. de Vest. Timisoara. Romania. Journal, 88(5) (1 September 2016). Cantor, M. (2016). Floriculture (in Romanian). Ed. https://doi.org/10.2985/015.088.0505 Academic Press, Cluj, Romania. Stead, J. (2016). The Succulent Garden Story. BioOne Change, L. (2012). Cacti and Succulents for Cold Complete. Cactus and Suculents Journal, 88(5) (1 Climates: 274 Outstanding Species for Challenging September 2016). https://doi.org/10.2985/015.088.0511 Conditions. Timber Press. ISBN-10: 604692642. Tawni, D. (2015). DIY Suculents. Adams Media. Simon Harvey, T. (2016). The Many Facets of Landscaping & Schuster. Inc 57. Avon. Massachusetts 02322. with Succulents. BioOne Complete. Cactus and USA. Suculents Journal, 88(5). (1 September 2016). Thulin, M. (2002). New species and combinations in https://doi.org/10.2985/015.088.0501 Kleinia (Asteraceae) from the Horn of Africa. Nordic Jacki, C. (2019). Punctuate your Garden with a Succulent Journal of Botany, Vol. 22, Issue 4, 419-426. Sphere. Drought Smart Plants Succulents: their Toma, F. (2009). Floriculture and Floral Art. Vol. 3. gardens and containers. https://www.drought-smart- Flower pots species for indoors (In Romanian). plants.com/succulent-sphere.html Publishing House Invel Multimedia. Lee, B.D. (2017). Deisgnis with suculents. Timber Press. Zeevaart, Jan A. D. (1982). Transmission of the Floral Portland. Oregon. 97204-3527. Stimulus from a Long-short-day Plant. Bryophyllum Maggio, M. (2016). Unbridled Discipline: Thoughts on daigremontianum. to the Short-long-day Plant Making a Great Succulent Garden. BioOne Echeveria harmsii. Vol. 49, No. 4 (April 1982), 549- Complete. Cactus and Suculents Journal, 88(5) (1 552 Published by: Oxford University Press. September 2016). https://doi.org/10.2985/015.088.0502 https://www.jstor.org/stable/42756773.

204